From patchwork Fri Nov 27 06:06:35 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wen Congyang X-Patchwork-Id: 549308 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4AA4E1402C3 for ; Fri, 27 Nov 2015 17:08:24 +1100 (AEDT) Received: from localhost ([::1]:54831 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1a2CCk-00076i-Dz for incoming@patchwork.ozlabs.org; Fri, 27 Nov 2015 01:08:22 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:35352) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1a2CCG-0006Od-AK for qemu-devel@nongnu.org; Fri, 27 Nov 2015 01:07:53 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1a2CCF-0006We-7v for qemu-devel@nongnu.org; Fri, 27 Nov 2015 01:07:52 -0500 Received: from [59.151.112.132] (port=26029 helo=heian.cn.fujitsu.com) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1a2CC9-0006VJ-GK; Fri, 27 Nov 2015 01:07:46 -0500 X-IronPort-AV: E=Sophos;i="5.20,346,1444665600"; d="scan'208";a="903908" Received: from unknown (HELO cn.fujitsu.com) ([10.167.33.5]) by heian.cn.fujitsu.com with ESMTP; 27 Nov 2015 14:07:28 +0800 Received: from G08CNEXCHPEKD01.g08.fujitsu.local (unknown [10.167.33.80]) by cn.fujitsu.com (Postfix) with ESMTP id 16CA14066D18; Fri, 27 Nov 2015 14:07:23 +0800 (CST) Received: from G08FNSTD140052.g08.fujitsu.local (10.167.226.52) by G08CNEXCHPEKD01.g08.fujitsu.local (10.167.33.89) with Microsoft SMTP Server (TLS) id 14.3.181.6; Fri, 27 Nov 2015 14:07:22 +0800 From: Wen Congyang To: qemu devel , Eric Blake , Alberto Garcia , Kevin Wolf , Stefan Hajnoczi Date: Fri, 27 Nov 2015 14:06:35 +0800 Message-ID: <1448604397-14975-2-git-send-email-wency@cn.fujitsu.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1448604397-14975-1-git-send-email-wency@cn.fujitsu.com> References: <1448604397-14975-1-git-send-email-wency@cn.fujitsu.com> MIME-Version: 1.0 X-Originating-IP: [10.167.226.52] X-yoursite-MailScanner-Information: Please contact the ISP for more information X-yoursite-MailScanner-ID: 16CA14066D18.ABDF5 X-yoursite-MailScanner: Found to be clean X-yoursite-MailScanner-From: wency@cn.fujitsu.com X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 59.151.112.132 Cc: qemu block , Jiang Yunhong , Dong Eddie , Markus Armbruster , "Dr. David Alan Gilbert" , Gonglei , zhanghailiang Subject: [Qemu-devel] [Patch v8 1/3] Add new block driver interface to add/delete a BDS's child X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org In some cases, we want to take a quorum child offline, and take another child online. Signed-off-by: Wen Congyang Signed-off-by: zhanghailiang Signed-off-by: Gonglei Reviewed-by: Eric Blake Reviewed-by: Alberto Garcia --- block.c | 50 +++++++++++++++++++++++++++++++++++++++++++++++ include/block/block.h | 5 +++++ include/block/block_int.h | 5 +++++ 3 files changed, 60 insertions(+) diff --git a/block.c b/block.c index 60ff84f..255a36e 100644 --- a/block.c +++ b/block.c @@ -4321,3 +4321,53 @@ void bdrv_refresh_filename(BlockDriverState *bs) QDECREF(json); } } + +/* + * Hot add/remove a BDS's child. So the user can take a child offline when + * it is broken and take a new child online + */ +void bdrv_add_child(BlockDriverState *parent_bs, BlockDriverState *child_bs, + Error **errp) +{ + + if (!parent_bs->drv || !parent_bs->drv->bdrv_add_child) { + error_setg(errp, "The node %s doesn't support adding a child", + bdrv_get_device_or_node_name(parent_bs)); + return; + } + + if (!QLIST_EMPTY(&child_bs->parents)) { + error_setg(errp, "The node %s already has a parent", + child_bs->node_name); + return; + } + + parent_bs->drv->bdrv_add_child(parent_bs, child_bs, errp); +} + +void bdrv_del_child(BlockDriverState *parent_bs, BlockDriverState *child_bs, + Error **errp) +{ + BdrvChild *child; + + if (!parent_bs->drv || !parent_bs->drv->bdrv_del_child) { + error_setg(errp, "The node %s doesn't support removing a child", + bdrv_get_device_or_node_name(parent_bs)); + return; + } + + QLIST_FOREACH(child, &parent_bs->children, next) { + if (child->bs == child_bs) { + break; + } + } + + if (!child) { + error_setg(errp, "The node %s is not a child of %s", + bdrv_get_device_or_node_name(child_bs), + bdrv_get_device_or_node_name(parent_bs)); + return; + } + + parent_bs->drv->bdrv_del_child(parent_bs, child_bs, errp); +} diff --git a/include/block/block.h b/include/block/block.h index d9b380c..06d3369 100644 --- a/include/block/block.h +++ b/include/block/block.h @@ -639,4 +639,9 @@ void bdrv_drained_begin(BlockDriverState *bs); */ void bdrv_drained_end(BlockDriverState *bs); +void bdrv_add_child(BlockDriverState *parent, BlockDriverState *child, + Error **errp); +void bdrv_del_child(BlockDriverState *parent, BlockDriverState *child, + Error **errp); + #endif diff --git a/include/block/block_int.h b/include/block/block_int.h index 6d7bd3b..ea20d12 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -302,6 +302,11 @@ struct BlockDriver { */ void (*bdrv_drain)(BlockDriverState *bs); + void (*bdrv_add_child)(BlockDriverState *parent, BlockDriverState *child, + Error **errp); + void (*bdrv_del_child)(BlockDriverState *parent, BlockDriverState *child, + Error **errp); + QLIST_ENTRY(BlockDriver) list; };